Novel nerve imaging and regional anesthesia, bio-impedance and the future

Artificial intelligence using deep neural network learning for automatic location of the interscalene brachial plexus in ultrasound images

BACKGROUND

Identifying the interscalene brachial plexus can be challenging during ultrasound-guided interscalene block.

OBJECTIVE

We hypothesised that an algorithm based on deep learning could locate the interscalene brachial plexus in ultrasound images better than a nonexpert anaesthesiologist, thus possessing the potential to aid anaesthesiologists.

DESIGN

Observational study.

SETTING

A tertiary hospital in Shanghai, China.

PATIENTS

Patients undergoing elective surgery.

INTERVENTIONS

Ultrasound images at the interscalene level were collected from patients. Two independent image datasets were prepared to train and evaluate the deep learning model. Three senior anaesthesiologists who were experts in regional anaesthesia annotated the images. A deep convolutional neural network was developed, trained and optimised to locate the interscalene brachial plexus in the ultrasound images. Expert annotations on the datasets were regarded as an accurate baseline (ground truth). The test dataset was also annotated by five nonexpert anaesthesiologists.

MAIN OUTCOME MEASURES

The primary outcome of the research was the distance between the lateral midpoints of the nerve sheath contours of the model predictions and ground truth.

RESULTS

The data set was obtained from 1126 patients. The training dataset comprised 11 392 images from 1076 patients. The test dataset constituted 100 images from 50 patients. In the test dataset, the median [IQR] distance between the lateral midpoints of the nerve sheath contours of the model predictions and ground truth was 0.8 [0.4 to 2.9] mm: this was significantly shorter than that between nonexpert predictions and ground truth (3.4 mm [2.1 to 4.5] mm; P < 0.001).

CONCLUSION

The proposed model was able to locate the interscalene brachial plexus in ultrasound images more accurately than nonexperts.

TRIAL REGISTRATION

ClinicalTrials.gov (https://clinicaltrials.gov) identifier: NCT04183972.

Application of ultrasound guidance in the oral and maxillofacial nerve block

Introduction

Nerve block technology is widely used in clinical practice for pain management. Conventional nerve localization methods, which only rely on palpation to identify anatomical landmarks, require experienced surgeons and can be risky. Visualization technologies like ultrasound guidance can help prevent complications by helping surgeons locate anatomical structures in the surgical area and by guiding the operation using different kinds of images. There are several important and complex anatomical structures in the oral and maxillofacial regions. The current article reviews the application of ultrasound guidance in oral and maxillofacial nerve blocks.

Methods

We searched the literature on the use of ultrasound guidance for the main nerve block techniques in the oral and maxillofacial regions using both PubMed and MEDLINE and summarized the findings.

Results and Discussion

A review of the literature showed that ultrasound guidance improves the safety and effectiveness of several kinds of puncture procedures, including nerve blocks. There are two approaches to blocking the mandibular nerve: intraoral and extraoral. This review found that the role of ultrasound guidance is more important in the extraoral approach. There are also two approaches to the blocking of the maxillary nerve and the trigeminal ganglion under ultrasound guidance: the superazygomatic approach and the infrazygomatic approach. The infrazygomatic approach can be further divided into the anterior approach and the posterior approach. It is generally believed that the anterior approach is safer and more effective. This review found that the effectiveness and safety of most oral and maxillofacial nerve block operations can be improved through the use of ultrasound guidance.

Education and training in ultrasound-guided regional anaesthesia and pain medicine

PURPOSE OF REVIEW

Effective and safe regional anaesthesia and pain medicine procedures require clinicians to learn and master complex theoretical knowledge and motor skills. This review aims to summarize articles relevant to education and training in these skill sets in the previous 2 years.

RECENT FINDINGS

Twenty-two articles were identified, investigating nine out of the 13 top-ranked research topics in education and training in regional anaesthesia. Research topics addressed by these articles included prerotation simulation, deliberate practice combined with formative assessment tools, validation of assessment tools, three-dimensional-printed models, and knowledge translation from simulation to clinical practice. Emerging concepts investigated for their applications in regional anaesthesia included eye-tracking as a surrogate metric when evaluating proficiency, and elastography aiding visual salience to distinguish appropriate perineural and inappropriate intraneural injections.

SUMMARY

Research into education and training in regional anaesthesia covered multiple and diverse topics. Methodological limitations were noted in several articles, reflecting the difficulties in designing and conducting medical education studies. Nonetheless, the evidence-base continues to mature and innovations provide exciting future possibilities.